Non-overweight Children Research Articles

Does being overweight impede academic attainment? A systematic review

Objectives: To examine evidence from studies exploring the relationship between childhood obesity and educational attainment. Design: A systematic review of secondary analyses and observational studies published in English after 1997 examining attainment as measured by grade point average or other validated measure, in children aged 6 to16 years, in high-income countries. Methods: Eleven databases from the fields of public health, education and social science were searched, along with 19 specialist registers and catalogues. Hand searching of relevant journals, contacting of experts and citation searching were undertaken. Two reviewers used standardized tools to independently carry out data extraction and assess the quality of included studies. Evidence was synthesized in a narrative summary. Results: Twenty-nine studies were identified for inclusion. Overall, the evidence suggested that higher weight is weakly associated with lower educational attainment among children and young people. Differences between average attainment of overweight and non-overweight children were marginal, with potentially negligible real-world implications for test scores. Limited evidence suggested that little variation in achievement was explained by weight status alone. Almost half the studies found that other factors, such as socioeconomic status, may better explain much of the negative association between obesity and attainment. Conclusion: Theoretical and methodological inconsistencies were evident both within and between many of the studies. As such, the results of the included studies must be interpreted with caution. If the negative association between obesity and attainment is accepted, it still remains doubtful whether obesity is exerting a socially important effect upon educational attainment.

Metabolic Syndrome in School Children

The problem of excessive weight and obesity is increasing world-wide. According to the World Health Organization (WHO), there are over 1.6 billion overweight and 400 million obese people in the world; in 2015, these figures are expected to reach 2.3 billion and 700 million, respectively. Ninety percent of obese adolescents are at risk of becoming obese adults; 75% of obese 12-year-olds go on to become obese adults; of 7-year-olds, 41% of obese ones become obese in adulthood; 25% of those obese in the pre-school period become obese adults; and 14% of obese infants are at risk of becoming obese adults. The presence of childhood obesity increases the risk of non-communicable diseases such as metabolic syndrome (MS), type 2 diabetes mellitus (DM), hypertension (HT), hyperlipidemia, cardiovascular disease, and certain cancers (1). In clinical studies, the prevalence of MS in childhood was found to be approximately 3-4%. The aim of the present study was to evaluate the prevalence of MS in southwest part of Turkey. This is a descriptive study conducted in the city center of Mardin in the South-eastern region of Turkey. Out of a total of 4030 students in three schools, 3460 (1668 female, 1792 male) volunteer children in the 6-15-year age group were surveyed for the study, and 86% of the targeted participants were reached. The data were collected in April and May of 2011. Weight, height, waist circumference (WC), and hip circumference (HC) were measured in all children according to standardized procedures. Age was calculated in decimal units based on the date of the survey relative to birth date. Body mass index (BMI) (kg/m2) was calculated with reference to measured height and weight and was evaluated using the WHO normative data for age and gender. Obesity was defined as BMI value exceeding ≥95th percentile, and BMI value between 85-95th percentiles was indicative of overweight (2). Blood pressure (BP) was obtained and evaluated according to standard methods. Abdominal obesity was defined using the sex- and age-specific 90th WC percentile values (3). Baseline blood samples were collected by venipuncture in the morning (8:00 to 9:00 am) after an overnight fast (10 to 12 hours). The glucose oxidase method was used to determine blood glucose levels. Serum lipids including total cholesterol, high-density lipoprotein cholesterol (HDL cholesterol), low-density lipoprotein cholesterol (LDL cholesterol), and triglycerides were measured using an enzymatic colorimetric method. MS was defined according to the International Diabetes Federation criteria (4) which have been used in several paediatric studies. Statistical analysis was performed with the SPSS statistical software and Microsoft Office Excel programs. A p-value of less than 0.05 was considered statistically significant. Ethical approval for the study was given by Mardin Artuklu University, Mardin Educational and Health Directorate Office. The female ratio of the study group was 48.2%. The average age of the students was 10.8±2.1 years, their mean height was 141.4±14.5 cm, their average weight was 37.6±13.24 kg, and their average BMI was 18.27±3.53 (range 11.28-42.08). According to their BMI values, the overweight frequency of the group was 9.4% (n=321). Frequency of obesity was 7.8% (n=269). The prevalence of obesity according to gender was found to be 8.8% (n=147) for female children and 6.8% (n=122) for male children and was significantly higher in girls (X2=7.244; p 0.05). Overweight and obese children had higher rates of MS than non-overweight children. In obese children, MS rate was 30.3%. The prevalence of overweight and obesity in the present study is similar to the figures in Turkey (2,5,6).

Differences in the effect of maternal smoking during pregnancy for childhood overweight before and after 5 years of age

This study aimed to clarify the association between maternal smoking during pregnancy and childhood overweight during different periods using two cohort studies from the same population: the birth cohort (the 1st cohort) and the non-overweight children at 5 years of age cohort (the 2nd cohort) by sex. The study population comprised children born between 1 April 1991 and 31 March 1999 in Koshu City, Yamanashi Prefecture, Japan, and their mothers. The dependent variables were diagnosis of overweight in each cohort. The primary independent variable was maternal smoking during pregnancy. Multiple logistic regression models were applied for these statistical analyses. Mothers who answered the questionnaire during early pregnancy gave birth to a total of 1644 babies during the study period. The 1st cohort consisted of these babies and were followed until 5 years of age. The 2nd cohort consisted of 1131 children who were diagnosed as normal weight at 5 years of age and followed until 9-10 years of age. There was an association between maternal smoking during pregnancy and overweight only in boys in the 1st cohort analysis (adjusted odds ratio, 4.5; 95% confidence interval, 2.0-10.2). These results suggest that the effects of maternal smoking during pregnancy on childhood overweight tend to appear before 5 years of age, especially in boys. It is necessary for children whose mother smoked during pregnancy, especially in boys, to be careful with their diet and physical activity in order to prevent childhood obesity.

Action Competence Obstacles to Managing Childhood Overweight: In-Depth Interviews With Mothers of 7- to 9-Year-Old Children

This qualitative phenomenological study interviewed seven mothers to overweight children and six mothers to non-overweight children aged 7 to 9 years old about their views and experiences with preventing and managing overweight in their children. The essence was that the mothers felt responsible for their children's habits, including those leading to overweight. They also felt that competent and had the opportunity to take preventive measures against child overweight but they did not always have the energy to do so. Even resourceful mothers required support from nurses and health professionals. Our results contribute to better understanding how to approach, motivate and support mothers to draw on their own competencies to benefit their children's weight and health.

An Objective Assessment of Children's Physical Activity During the Keep It Moving! After‐School Program

After-school programs may provide valuable opportunities for children to accumulate healthful physical activity (PA). This study assessed the PA of third-, fourth-, and fifth-grade children in the Keep It Moving! (KIM) after-school PA program, which was implemented in an ethnically diverse and low socioeconomic status school district in Colorado Springs, Colorado. The PA of KIM participating children (N = 116) at 4 elementary schools was objectively assessed using ActiGraph accelerometers and the System for Observing Fitness Instruction Time (SOFIT). Linear mixed-effects models or generalized linear mixed-effects models were used to compare time spent in sedentary (SED) behaviors, light PA (LPA), moderate PA (MPA), vigorous PA (VPA), and moderate-to-vigorous PA (MVPA) between genders and weight status classifications during KIM sessions. Children accumulated 7.6 minutes of SED time, 26.9 minutes of LPA, and 22.2 minutes of MVPA during KIM sessions. Boys accumulated less SED time (p < .05) and LPA (p = .04) than girls, but accumulated more MPA (p = .04), VPA (p = .03), and MVPA (p = .03). Overweight/obese children accumulated more LPA (p = .04) and less VPA (p < .05) than nonoverweight children. SOFIT data indicated that children spent a considerable proportion of KIM sessions being very active (12.4%), walking (36.0%), or standing (40.3%). The KIM program provides opportunities for disadvantaged children to accumulate substantial amounts of MVPA (>20 minutes per session) in an effort to meet current PA guidelines.

Non-overweight and overweight children’s physical activity during school recess

Objective: Little research has investigated children’s physical activity levels during school recess and the contribution of recess to school day physical activity levels by weight status. The aims of this study were to examine non-overweight and overweight children’s physical activity levels during school recess, and examine the contribution of recess to school day physical activity. Design: Cross-sectional. Setting: Four elementary schools located in Nebraska, United States of America (USA). Methods: Two hundred and seventeen children (99 boys, 118 girls; 47.9% overweight) wore a uni-axial accelerometer for five consecutive school days during autumn 2009. The proportion of time spent engaged in sedentary (SED), light (LPA), moderate (MPA) and vigorous (VPA) intensity physical activity during recess was determined using age-specific accelerometer thresholds. Results: Overweight children engaged in more %MPA and less %VPA than non-overweight children, respectively. No differences were found between overweight and healthy weight children’s moderate-to-vigorous physical activity (MVPA). Recess contributed 16.9% and 16.3% towards non-overweight and overweight children’s school day %MVPA, respectively. Conclusion: Examining %MVPA as an outcome variable may mask differences in recess physical activity levels between non-overweight and overweight children. Future research is needed to establish why healthy weight and overweight children engage in differing levels of %MPA and %VPA during recess.

“Obese Equals Lazy?” Analysis of the Association between Weight Status and Physical Activity in Children

Introduction. Literature provides evidence that overweight children are more sedentary. To verify this generalized statement behavior patterns of overweight and nonoverweight children needs to be understood. Therefore, we investigated the distribution of sedentary and activity levels in a quantitative and qualitative way. Methods. Data was collected from 37 randomly selected nonoverweight and 55 overweight children. They were 8 to 11 years of age. Height and weight were measured and weight status was characterized by BMI (BMI-percentile, BMI-SDS). Daily PA (physical activity) was measured by direct accelerometry. Spare time and screen time entertainment were obtained by questionnaires. Results. The amount of time spent “passive” was significantly higher in overweight children, while nonoverweight children were more “active.” The multiple regression model shows a significant association between weight status (BMI-SDS) and activity parameters. Additionally, screen time entertainment was significantly related to BMI-SDS. Conclusion. The results support the statement that overweight children are less active than nonoverweight children. The high amount of PA seems to be an important factor to prevent overweight in children given that PA shows the highest correlation to weight status. Quantitative and qualitative measurements are needed for further analysis.

Limitations of Expressing Left Ventricular Mass Relative to Height and to Body Surface Area in Children

Left ventricular (LV) mass varies in proportion to lean body mass (LBM) but is usually expressed relative to height or body surface area (BSA), each of which functions as a surrogate for LBM. The aims of this study were to characterize the adiposity-related biases associated with each of these scaling variables and to determine the impact of these biases on the diagnosis of LV hypertrophy (LVH) in a group of children at risk for LVH. In a retrospective study, LV mass was estimated using M-mode echocardiography in 222 healthy nonoverweight reference children and 112 children "at risk" for LVH (48 healthy overweight children and 64 children with hypertension). LBM was estimated for all children using validated predictive equations and was considered the criterion scaling variable. Z scores for LV mass for LBM, LV mass for height, and LV mass for BSA were calculated for each child relative to the reference group. The performance of height-based and BSA-based Z scores were compared with that of LBM-based Z scores at different levels of adiposity (estimated by the Z score for body mass index for age [BMIz]). Among healthy normotensive children, LV mass-for-height Z scores were greater than LV mass-for-LBM Z scores at higher values of BMIz and lower than LV mass-for-LBM Z scores at lower values of BMIz (R(2)= 0.52, P < .0001). LV mass-for-BSA Z scores for agreed well with LBM-based Z scores at BMIz < 0.7 but were lower than LV mass-for-LBM Z scores for at BMIz > 0.7 (R(2)= 0.31, P < .0001). Compared with 13% of at-risk children classified as having LVH on the basis of LV mass for LBM > 95th percentile, 30% and 11% had LVH when LV mass was scaled to height and BSA, respectively. Scaling LV mass to BSA in children results in less misclassification with respect to LVH than does scaling to height.

The Prevalence of Metabolic Syndrome in Children: A Systematic Review of the Literature

Metabolic syndrome has been identified as a condition of childhood relatively recently. The aim in this study was to describe the prevalence of metabolic syndrome in children allowing for differences in metabolic syndrome definitions. This was a systematic review of the OVID, EMBASE, and CINAHL databases, capturing details of overall prevalence and prevalence within groups categorized by obesity, gender, age, and ethnicity. In all, 378 studies published since 2003 were identified, and of these 85 papers were included in the present review. When all studies were considered, the median prevalence of metabolic syndrome in whole populations was 3.3% (range 0%-19.2%), in overweight children was 11.9% (range 2.8%-29.3%), and in obese populations was 29.2% (range 10%-66%). Within-study analyses confirmed higher prevalence for obese compared to overweight (P=0.012) and obese compared to nonobese, nonoverweight children (P<0.001). Within-study analyses also revealed higher median metabolic syndrome prevalence for boys compared to girls (5.1% versus 3.0%, P<0.001) and also in older compared with younger children (5.6% versus 2.9%, P=0.001). Limited evidence was found to suggest differences between ethnic groups, and there were insufficient studies to determine whether metabolic syndrome prevalence was increasing over time. This is the first systematic review of all of the relevant literature. It describes the magnitude of associations between metabolic syndrome and obesity, age, and gender. We find evidence that ethnicity and geography may be important to metabolic syndrome prevalence in children and these associations require further study.

S30 Does Obesity Make For Worse Childhood Asthma?

IntroductionObesity may be important to asthma causation but the relationship between obesity and outcomes within populations of children with established asthma is inconsistent across studies. This study tested the hypothesis...

Gender difference of childhood overweight and obesity in predicting the risk of incident asthma: a systematic review and meta‐analysis

The aims of our meta-analysis were (i) to quantify the predictability of childhood overweight and obesity on the risk of incident asthma; and (ii) to evaluate the gender difference on this relationship. The selection criteria included prospective cohort paediatric studies which use age- and sex-specific body mass index (BMI) as a measure of childhood overweight and the primary outcome of incident asthma. A total of 1,027 studies were initially identified through online database searches, and finally 6 studies met the inclusion criteria. The combined result of reported relative risk from the 6 included studies revealed that overweight children conferred increased risks of incident asthma as compared with non-overweight children (relative risk, 1.19; 95% confidence interval [CI], 1.03-1.37). The relationship was further elevated for obesity vs. non-obesity (relative risk, 2.02; 95% CI, 1.16-3.50). A dose-responsiveness of elevated BMI on asthma incidence was observed (P for trend, 0.004). Obese boys had a significantly larger effect than obese girls (relative risk, boys: 2.47; 95% CI, 1.57-3.87; girls: 1.25; 95% CI, 0.51-3.03), with significant dose-dependent effect. Proposed mechanisms of gender difference could be through pulmonary mechanics, sleep disordered breathing and leptin. Further research might be needed to better understand the exact mechanism of gender difference on the obesity-asthma relationship.

Residents' journal review

Residents' journal review

361 Overweight and Scholastic Achievement in Chilean School-Age Children

Background and AimsOverweight has been linked to health problems and deteriorate school outcomes. Some studies show that overweight school-age children have lower scholastic achievement (SA) but the evidence is controversial....

The oxygen uptake kinetic response to moderate intensity exercise in overweight and non-overweight children

To compare the phase II oxygen uptake time constant (τV'O(2)) and V'O(2) mean response time (V'O(2)MRT) in overweight (OW) and non-OW (NO) children during moderate intensity exercise. Between subjects where participants completed a maximal ramp exercise test on an electromagnetically braked cycle ergometer to determine peak V'O(2) (V'O(2peak)) and gas exchange threshold (GET). Gas exchange was measured breath-by-breath using a mass spectrometer. On subsequent visits, 6 square-wave transitions (2 per day) from 0 W to 90% GET were completed. Individual phase II τV'O(2) and V'O(2)MRTs were estimated from time aligned average V'O(2) traces. Eleven OW (11.8±0.4 years) and 12 NO (11.9±0.4 years) children were recruited to the study. The OW group was significantly heavier (62.9±9.7 vs 39.4±5.8 kg, P<0.001), taller (1.58±0.05 vs 1.47±0.07 m, P<0.001) and had a higher body mass index (25.8±3.4 vs 18.3±1.8 kg m(-2), P<0.001). Both τV'O(2) (30.2±9.6 vs 22.8±7.1 s, P<0.05) and V'O(2)MRT (43.5±10.7 vs 36.3±5.3 s, P<0.05) were significantly slower in OW compared with NO children; absolute V'O(2peak) was higher in the OW compared with NO group (2.23±0.04 vs 1.74±0.04 l min(-1), P<0.05); mass relative V'O(2peak) was lower in OW compared with NO children (35.9±8.3 vs 43.8±6.2 ml kg(-1) min(-1), P<0.05); allometrically scaled V'O(2peak) was similar between OW and NO groups whether relative to body mass(0.67) (139.8±29.1 vs 147.2±23.9 ml kg(-67) min(-1)) or stature(3) (576.0±87.2 vs 544.9±84.9 ml m(-3) min(-1)) (P>0.05); absolute V'O(2) at GET was similar between OW and NO groups (0.94±0.24 vs 0.78±0.27 l min(-1), P>0.05); GET expressed as percentage of V'O(2peak) was similar between the groups (42.0±0.1 vs 44.8±0.1%, P>0.05). These findings demonstrate impairment in the factors determining V'O(2) kinetics in OW children at a relatively young age. Furthermore, assessment of cardiorespiratory fitness using peak exercise values is likely to be misleading and not useful when designing exercise programmes for OW children.

Determinants of (sustained) overweight and complaints in children and adolescents in primary care: the DOERAK cohort study design

BackgroundAlmost half of the adult Dutch population is currently overweight and the prevalence of overweight children is rising at alarming rates as well. Obese children consult their general practitioner (GP) more often than normal weight children. The Dutch government has assigned a key role to the GP in the prevention of overweight.The DOERAK cohort study aims to clarify differences between overweight and non-overweight children that consult the GP; are there differences in number of consultations and type and course of complaints? Is overweight associated with lower quality of life or might this be influenced by the type of complaint? What is the activity level of overweight children compared to non-overweight children? And is (sustained) overweight of children associated with parameters related to the energy balance equation?Methods/DesignA total of 2000 overweight (n = 500) and non-overweight children (n = 1500) aged 2 to 18 years who consult their GP, for any type of complaint in the South-West of the Netherlands are included.At baseline, height, weight and waist circumference are measured during consultation. The number of GP consultations over the last twelve months and accompanying diagnoses are acquired from the medical file. Complaints, quality of life and parameters related to the energy balance equation are assessed with an online questionnaire children or parents fill out at home. Additionally, children or parents keep a physical activity diary during the baseline week, which is validated in a subsample (n = 100) with an activity monitor. Parents fill out a questionnaire about demographics, their own activity behaviour and perceptions on dietary habits and activity behaviour, health and weight status of their child. The physical and lifestyle behaviour questions are repeated at 6, 12 and 24 months follow-up.The present study is a prospective observational cohort in a primary care setting.DiscussionThe DOERAK cohort study is the first prospective study that investigates a large cohort of overweight and non-overweight children in primary care. The total study population is expected to be recruited by 2013, results will be available in 2015.

Vitamin D Deficiency in Obese Children and Its Relationship to Glucose Homeostasis

Obesity in adults and children is associated with high rates of vitamin D deficiency. The relationship of mechanisms of glucose homeostasis to this association is poorly understood. This cross-sectional study was designed to compare the prevalence of vitamin D deficiency in obese and nonoverweight children in North Texas, and also to examine the association between dietary habits and serum 25-hydroxyvitamin D (25(OH)D) levels and correlations between 25(OH)D levels and markers of glucose homeostasis and blood pressure in obese children. The clinical parameters examined included serum 25(OH)D, dietary information, homeostasis model assessment of insulin resistance, 2-hour glucose from oral glucose tolerance test, hemoglobin A1c, fasting glucose and insulin, and systolic and diastolic blood pressures. Participants were 411 obese subjects (aged 6–16 years) examined at an obesity referral clinic. Levels of 25(OH)D also were measured in 87 matched control nonoverweight subjects (aged 6–16 years). Obese subjects with a 25(OH)D level below 50 nmol/L were considered to be vitamin D deficient, and those with a level below 75 nmol/L were classified as vitamin D insufficient. More than 90% of obese subjects were vitamin D insufficient (25(OH)D level <75 nmol/L) and 50% were vitamin D deficient (25(OH)D level <50 nmol/L). Significantly fewer control subjects were vitamin D insufficient or deficient (both P < 0.01 compared with obese subjects). A negative association was found between 25(OH)D levels and the dietary measures of soda intake, juice intake, and skipping breakfast (each comparison P < 0.001). After adjustment for body mass index and age, 25(OH)D levels were negatively correlated with homeostasis model assessment of insulin resistance (r = −0.19; P = 0.001) and 2-hour glucose (r = −0.12; P = 0.04. There was no correlation between 25(OH)D and hemoglobin A1c, systolic blood pressure Z score, or diastolic blood pressure Z score. These findings show that vitamin D deficiency is significantly more prevalent in a population of obese children than in nonoverweight children. The inverse association between 25(OH)D levels with both insulin resistance and 2-hour glucose levels suggest that low 25(OH)D levels may play a role in the pathophysiology of impaired glucose tolerance or type 2 diabetes in obese children.

Rapid maxillary expansion before and after adenotonsillectomy in children with obstructive sleep apnea

Adenotonsillectomy is not always successful in controlling obstructive sleep apnea (OSA) in children, and orthodontic treatment may be a helpful adjunction and sometime an important alternative. A total of 80 nonoverweight children (37 girls) with a high and narrow hard palate, based on an indepth orthodontic evaluation, were subdivided into two groups based on presence/absence of chronic adenotonsillar inflammatory problems as determined by full otolaryngological examination, with recruitment of 40 children in each group. Patients with evidence of chronic inflammation were treated with adenotonsillectomy first (group II), while all other children had rapid maxillary expension (RME) first (group I). In all children, clinical interviews and clinical evaluations, frontal and lateral cephalometry, and polysomnography were performed at entry. Four months after end of treatment, the initial evaluation was repeated in all children. Children incompletely treated were offered to cross-over to the other treatment venue. At entry, there was no significant difference between the monitored respiratory polygraphic variables between the two groups. At the 4-month follow-up, 15 subjects treated with RME were considered as cured compared to 6 patients after adenotonsillectomy, and absence of improvement was observed in 8 children with RME and 16 with adenotonsillectomy. After cross-over to the other treatment, involving 42 subjects due to 17 drop-outs between treatment 1 and 2,, three children were still having residual sleep disordered breathing at the 12-month follow-up, while normal breathing during sleep was observed in all others. With appropriate clinical investigation, prepubertal children with OSA and narrow maxilla may have better treatment outcome when treated with orthodontics than with adenotonsillectomy; and polygraphic and even better polysomnographic documentation of clinical impression is always needed posttreatment.

Lack of Association of Type 2 Diabetes Susceptibility Genotypes and Body Weight on the Development of Islet Autoimmunity and Type 1 Diabetes

AimTo investigate whether type 2 diabetes susceptibility genes and body weight influence the development of islet autoantibodies and the rate of progression to type 1 diabetes.MethodsGenotyping for single nucleotide polymorphisms (SNP) of the type 2 diabetes susceptibility genes CDKAL1, CDKN2A/2B, FTO, HHEX-IDE, HMGA2, IGF2BP2, KCNJ11, KCNQ1, MTNR1B, PPARG, SLC30A8 and TCF7L2 was obtained in 1350 children from parents with type 1 diabetes participating in the BABYDIAB study. Children were prospectively followed from birth for islet autoantibodies and type 1 diabetes. Data on weight and height were obtained at 9 months, 2, 5, 8, 11, and 14 years of age.ResultsNone of type 2 diabetes risk alleles at the CDKAL1, CDKN2A/2B, FTO, HHEX-IDE, HMGA2, IGF2BP2, KCNJ11, KCNQ1, MTNR1B, PPARG and SLC30A8 loci were associated with the development of islet autoantibodies or diabetes. The type 2 diabetes susceptible genotype of TCF7L2 was associated with a lower risk of islet autoantibodies (7% vs. 12% by age of 10 years, P = 0.015, Pcorrected = 0.18). Overweight children at seroconversion did not progress to diabetes faster than non-overweight children (HR: 1.08; 95% CI: 0.48–2.45, P>0.05).ConclusionsThese findings do not support an association of type 2 diabetes risk factors with islet autoimmunity or acceleration of diabetes in children with a family history of type 1 diabetes.

The contribution of school breaks to the all-day physical activity of 9- and 10-year-old overweight and non-overweight children

ObjectivesThis study examines whether moderate-to-vigorous physical activity (MVPA), in at least 30-min school breaks (SB), helps to achieve the health-related amount of daily physical activity (PA) and whether these exercises influence after-school PA.MethodsThe ActiTrainer-based PA was monitored over two school days in 239 children aged from 9 to 10 (57.3% female; 20.1% overweight, and 19.2% obese), in Katowice, in February 2010. PA was assessed based on steps, heart rate, and duration of PA.ResultsMVPA, for 30 min during SB, represented an average of 1,258 steps for overweight girls and 1,620 steps for boys, and 1,336 steps for non-overweight girls and 1,758 steps for boys. Children with 30 min of MVPA during SB attained a higher daily amount of steps (p < 0.001) and duration of overall PA (p < 0.01), in comparison with less physically active children.ConclusionThe daily 30 min of MVPA during SB amounts to 12.5% of the overall number of steps for girls and 16.3% for boys, thus contributing to higher school PA and overall PA and leading to the achievement of the health-related minimum of PA.

Exclusive breastfeeding duration and cardiorespiratory fitness in children and adolescents

Breastfeeding has been associated with a protective effect against cardiovascular disease. Higher cardiorespiratory fitness during childhood is associated with healthier cardiovascular profile later in life. The objective was to examine the association of exclusive breastfeeding duration with fitness in children and adolescents and to test the role of body composition and sociodemographic factors in this relation. At the time of the study, exclusive breastfeeding duration was reported by mothers and grouped into 4 categories: exclusively formula fed or breastfed for <3, 3-6, or >6 mo. Fitness was determined by a maximal cycle-ergometer test in 1025 children (aged 9.5 ± 0.4 y) and in 971 adolescents (aged 15.5 ± 0.5 y) from Estonia and Sweden. Longer duration of breastfeeding was associated with higher fitness regardless of confounders [+5.1% L/min; country, sex, age, pubertal status, and BMI (adjusted P < 0.001) or fat mass and fat-free mass (FFM) (+3.3%; adjusted P < 0.001)]. Further adjustment for birth weight, physical activity, and maternal educational level did not change the results (P = 0.001). The results were consistent in children and adolescents with low (P < 0.001) or high (P = 0.013) FFM, in nonoverweight (P < 0.001) or overweight (P = 0.002) children and adolescents, in offspring of nonoverweight (P < 0.001) or overweight (P = 0.003) mothers, in mothers with a low (P = 0.004) or high (P < 0.001) educational level, and in participants born within upper (P = 0.001), middle (P = 0.017), or lower (P = 0.007) tertiles of birth weight. Longer exclusive breastfeeding has a beneficial effect on cardiorespiratory fitness in children and adolescents. Because early infant-feeding patterns are potentially modifiable, a better understanding of the possible programming effect of exclusive breastfeeding on cardiorespiratory fitness is of public health interest.